(a) Technical Field
This disclosure relates to the field of semiconductor processing and more in particular to connectors to be used in a clean environment
(b) Description of the Related Art
In semiconductor processing, vertical furnaces are used for batch processing of wafers. In such furnaces, a boat holding a vertical stack of wafers, accommodated in a wafer boat, the wafer boat being supported on a door plate is inserted into the furnace from below. The door plate may be provided with provisions such as a boat rotation mechanism, door plate heating and temperature sensors. These provisions require electrical connections. In the art, such a connection is made through a long flexible cable that hangs in a loop so as to allow for the vertical up and down movement of the door plate. This implies that a significant length of the cable is exposed to an environment immediately below the furnace. As the wafers to be processed are exposed to this environment, this environment is a mini-environment required to maintain clean air circulation. Into this mini-environment a hot batch of wafers is unloaded after completion of processing. As a consequence, the long flexible cable having an isolation mantle and cable guiding means, is regularly exposed to heat radiation. Therefore, the long flexible cable may get heated and outgas, thereby resulting in contamination of the mini-environment and, possibly, contamination of the wafers, which is undesirable. In an attempt to avoid this contamination, the connection through a long flexible cable in a loop was replaced by a connection made through a connector. The connector has a movable connector part mounted on the movable door plate and a fixed connector part. The two connector parts mate and make contact when the door plate is in an upper, sealing position. The cable to the fixed part of the connector can be stationary and has a strongly reduced risk of outgassing and contamination. However, the connector parts, comprising pins that make a sliding movement in sockets during the action of making contact, is appeared to generate particles. Even though the global circulation of filtered air is present in the mini-environment, it appears to be insufficient to prevent the wafers from being contaminated with particles.